Natural plant products protect skin during radiotherapy

Three ubiquitous and well-studied natural products derived from plants can protect the skin against gamma radiation during radiotherapy, according to new research.

Radiotherapy for cancer involves exposing the patient or their tumor more directly to ionizing radiation, such as gamma rays or x-rays. The radiation damages the cancer cells irreparably. Unfortunately, such radiation is also harmful to healthy tissue, particularly the skin over the site of the tumor, which is then at risk of hair loss, dermatological problems, and even skin cancer. So, researchers are seeking ways to protect the overlying skin.

Writing in the International Journal of Low Radiation (2014; 9(4):305-316), Faruck Lukmanul Hakkim, PhD, of the University of Nizwa in Oman and Nagasaki University in Japan, and international colleagues examined these three plant-derived products and how they can protect the skin during gamma radiation.

Hakkim and colleagues discussed the benefits of the antioxidant compounds caffeic acid, rosmarinic acid, and trans-cinnamic acid. They tested the radio-protective effects of these compounds against gamma-radiation by examining their ability to reduce the levels of reactive oxygen species generated in skin cells. Their tests used clinically relevant doses of gamma rays, which can cause damage to DNA. They specifically examined double-strand breaks in DNA of laboratory samples of human skin cells (keratinocytes).

They found that human skin cells were protected from gamma ray toxicity by treatment with caffeic acid by 40%, rosmarinic acid by 20%, and trans-cinnamic acid by 15%. They suggested that the protective effect arises because the compounds mop up the reactive oxygen species and chemically deactivate them. They also suggested that the compounds enhance the body's natural DNA repair mechanisms.

The team suggested that these compounds might best be used as skin protectants during combination chemo- and radiotherapy. Further work is under way to investigate the clinical potential of mixtures of the three natural products.